SYSTEM DESCRIPTION
BRC-41
[VDC/TCS/ABS]
C
D
E
G
H
I
J
K
L
MA
B
BRC
SYSTEM DESCRIPTIONPFP:00000
System DiagramBFS000DP
FunctionsBFS000DQ
VDC
In addition to the TCS/ABS function, the steering amount and brake operation amount are detected from
the steering angle sensor and brake switch, and the driving condition (amount of under-steering/over-
steering) is determined from information from the yaw rate/side/decel G sensor, vehicle speed sensor, etc.
This information is used to improve vehicle stability by controlling the braking and engine power to all four
wheels.
The SLIP indicator lamp flashes to inform the driver of VDC operation.
During VDC operation, the body and brake pedal lightly vibrate and mechanical noises may be heard.
This is normal.
ABS warning lamp, VDC OFF indicator lamp, and SLIP indicator lamp might turn on when the vehicle is
subject to strong shaking or large vibration, such as when the vehicle is on a turn table or a ship while
engine is running. In this case, restart engine on a normal road, and if ABS warning lamp, VDC OFF indi-
cator lamp, and SLIP indicator lamp turn off, there is no malfunction.
TCS
Speed signals for 4 wheels control engine output and transaxle conditions so that slip rate of the drive
wheels is optimum. ABS actuator and electric unit (control unit) detects wheelspin. Output from the control
unit controls brake fluid pressure to both LH and RH drive wheels while cutting fuel to the engine and clos-
ing the throttle valve to reduce engine torque when wheelspin is detected. Throttle position is continuously
controlled to ensure the appropriate engine torque at all times.
Depending on road conditions, the driver may have a sluggish feel. This is normal, because the optimum
traction has the highest priority by TCS operation.
TCS may be activated momentarily the vehicle suddenly accelerates, suddenly downshifts, or is driven on
a road with a varying surface friction coefficient.
During TCS operation, it informs a driver of system operation by flashing SLIP indicator lamp.
SFIA3329E
TROUBLE DIAGNOSIS
BRC-65
[VDC/TCS/ABS]
C
D
E
G
H
I
J
K
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MA
B
BRC
For Fast and Accurate DiagnosisBFS000E6
PRECAUTIONS FOR DIAGNOSIS
Be sure to check the procedures of “How to Perform Trouble Diagnosis” in advance. Refer to GI-4, "Gen-
eral Precautions" .
Always adjust the neutral position of steering angle sensor before driving when removing and installing
ABS actuator and electric unit (control unit), steering angle sensor, suspension parts and adjusting align-
ment. Refer to BRC-40, "
Adjustment of Steering Angle Sensor Neutral Position" .
Always erase memory after completing trouble diagnosis. Refer to BRC-58, "ERASE MEMORY" .
When inspection of the continuity or voltage between modules or units is performed, check connector ter-
minals for disconnection, looseness, bend, or collapse. Repair or replace applicable part if any non-stan-
dard condition is detected.
Intermittent malfunctions may be caused by a poor connection in the harness, connectors, and terminals.
Move harnesses, harness connectors, and terminals by hand to make sure all connections are solid and
undamaged.
Do not to forcibly extend any connector terminal if a circuit tester is used for the check.
The symptom shown in the table may occur, but the system is operating normally.
Symptom Symptom description Result
Motor operation soundThis is the operation sound of the motor in the actuator and electric unit.Slight
sound may occur during VDC, TCS and ABS operation.
Normal
Just after the engine starts, the motor operating noise may be heard. This is a
normal status of the system operation check.
System operation check soundWhen engine starts, “click” sound may be heard from engine room. This is nor-
mal status of system operation check.Normal
VDC/TCS operation
(SLIP indicator lamp ON)TCS may activate momentarily if wheel speed changes when driving over
location where friction coefficient varies, when downshifting, or when fully
depressing accelerator pedal.
Normal
Cancel the VDC/
TCS function for
the inspection on
a chassis dyna-
mometer. Before the speed meter inspection, push VDC OFF switch to cancel the VDC/
TCS function.
When accelerator pedal is depressed on a chassis dynamometer (front wheel
fixing type), the vehicle speed will not increase. This is normal. It is result of
TCS being activated by stationary front wheels. The warning lamp may also
turn on to show “sensor system malfunction” in this case. This is also normal,
and is the result of the stationary front wheels being detected. Restart engine,
and drive the vehicle at 30 km/h (19 MPH) or more to make sure that the warn-
ing lamp no longer turns on.
ABS operation
(Longer stopping distance)When driving on roads with a low coefficient of friction, such as snowy roads or
gravel roads, the stopping distance is sometimes longer for vehicles equipped
with ABS. Therefore, when driving on such roads, drive at a sufficiently
reduced speed to be safe.Normal
Sluggish feelDepending on road conditions, the driver may have a sluggish feel. This is
because traction control, which controls engine and brakes to achieve optimal
traction, has the highest priority (for safety). As a result sometimes the driver
has a less slight sluggish feel in response than usual acceleration feel.Normal